The apartment was an excellent value. As a solo traveler, a private hostel room would actually cost more (and decent hotel double).
It was extremely easy to find, even at 3 AM from the airport (AIS SIM card, 300B at airport = beyond valuable for map reassurance).
The apartment was clean, bright and advertised. The street was amazingly quiet. There are a few bars and restaurants around. Silom is 40-60B motorbike/taxi away.
John replied promptly and his help did come by to open the safe. I'd book again.